Project description:Global warming substantially changes precipitation patterns in the Tibetan plateau, with projection of increased precipitation in southern and northern Tibet but decreased precipitation in the center. Understanding mechanisms of such changes in greenhouse gas emissions is of vital importance in predicting ecosystem feedbacks to climate changes. Nonetheless, it has been hampered by limited knowledge in soil microbial communities, one of the major drivers of greenhouse gas emission. Here, we report a field experiment simulating drying and wetting conditions in the Tibetan grassland. Our field site is located at the Haibei Alpine Grassland Ecosystem Research Station in the northeast of Tibet Plateau, China, and we employed GeoChip 5.0 180K to analyze microbial responses.
Project description:To study long-term elevated CO2 and enriched N deposition interactive effects on microbial community and soil ecoprocess, here we investigated soil microbial community in a grassland ecosystem subjected to ambient CO2 (aCO2, 368 ppm), elevated CO2 (eCO2, 560 ppm), ambient nitrogen deposition (aN) or elevated nitrogen deposition (eN) treatments for a decade. There exist antagonistic CO2×N interactions on microbial functional genes associated with C, N, P S cycling processes. More strong antagonistic CO2×N interactions are observed on C degradation genes than other genes. Remarkably antagonistic CO2×N interactions on soil microbial communities could enhance soil C accumulation.
Project description:Global warming substantially changes precipitation patterns in the Tibetan plateau, with projection of increased precipitation in southern and northern Tibet but decreased precipitation in the center. Understanding mechanisms of such changes in greenhouse gas emissions is of vital importance in predicting ecosystem feedbacks to climate changes. Nonetheless, it has been hampered by limited knowledge in soil microbial communities, one of the major drivers of greenhouse gas emission. Here, we report a field experiment simulating drying and wetting conditions in the Tibetan grassland. Our field site is located at the Haibei Alpine Grassland Ecosystem Research Station in the northeast of Tibet Plateau, China, and we employed GeoChip 5.0 180K to analyze microbial responses. 18 samples were collected from 3 plots in Haibei Station, with 6 replicates in each plot
Project description:Starchy endosperm proteins determine wheat quality and exhibit, besides a quantitative protein gradient, a qualitative protein gradient from the outer to inner starchy endosperm. The goal was to investigate the relative differences in protein composition between the aleurone, sub-aleurone and inner endosperm. Using laser microdissection followed by nanoLC-MS/MS, an innovative method combining a high spatial specificity and analytical selectivity in sample-limited situations, 780 proteins were detected and classified by function. Relatively more gluten proteins were detected in the sub-aleurone compared to inner endosperm. Gluten composition-wise, the sub-aleurone is relatively more enriched in ω-gliadins, but impoverished in LMW-GS and γ-gliadins. While a basic set of albumins and globulins is detected across the entire endosperm, some proteins, like puroindoline-B, display an increasing (or decreasing) gradient. Histological origin and relative positioning of the endosperm cells are hypothesized to drive the protein gradient. Knowledge on this gradient provides major opportunities for the wheat manufacturing industry.
Project description:It is assumed that climate and land-use changes cause increasing stress to pollinators, which play pivotal roles in almost all terrestrial ecosystems, with consequences on population growth, diversity and ecosystem functions. While these responses to global change drivers are well located, the molecular pathways triggering the response are poorly understood. We analysed the transcriptomic response of Bombus lucorum workers in their systematic responses to temperature and livestock grazing, sampled along an elevational gradient from 650 – 1930 m.a.s.l., and from differently managed grassland sites (livestock grazing vs. unmanaged) in and around the National Park Berchtesgaden (German Alps).
Project description:The altitude gradient limits the growth and distribution of alpine plants.Alpine plants have developed strategies to survive the extremely cold conditions prevailing at high altitudes; however, the mechanism underlying the evolution of these strategies remains unknown. The alpine plant Potentilla saundersiana is widespread in the Northwestern Tibetan Plateau. In this study, we conducted a comparative proteomics analysis to investigate the dynamic patterns of protein expression of P. saundersiana located at five different altitudes. We detected and functionally characterized 118 differentially expressed proteins. Our study confirmed that increasing levels of antioxidant proteins, and their respective activities, and accumulation of primary metabolites, such as proline and sugar, confer tolerance to the alpine environment in P. saundersiana. Proteins species associated with the epigenetic regulation of DNA stability and post-translational protein degradation were also involved in this process. Furthermore, our results showed that P. saundersiana modulated the root architecture and leaf phenotype to enhance adaptation to alpine environmental stress through mechanisms that involved hormone synthesis and signal transduction, particularly the cross-talk between auxin and strictosidine. Based on these findings, we conclude that P. saundersiana uses multiple strategies to adapt to the high-altitude environment of the Northwestern Tibetan Plateau.
Project description:Plant respiration responses to elevated growth [CO2] are key uncertainties in predicting future crop and ecosystem function. In particular, the effects of elevated growth [CO2] on respiration over leaf development are poorly understood. This study tested the prediction that, due to greater whole-plant photoassimilate availability and growth, elevated [CO2] induces transcriptional reprogramming and a stimulation of nighttime respiration in leaf primordia, expanding leaves, and mature leaves of Arabidopsis thaliana. In primordia, elevated [CO2] altered transcript abundance, but not for genes encoding respiratory proteins. In expanding leaves, elevated [CO2] induced greater glucose content and transcript abundance for some respiratory genes, but did not alter respiratory CO2 efflux. In mature leaves, elevated [CO2] led to greater glucose, sucrose and starch content, plus greater transcript abundance for many components of the respiratory pathway, and greater respiratory CO2 efflux. Therefore, growth at elevated [CO2] stimulated dark respiration only after leaves transitioned from carbon sinks into carbon sources. This coincided with greater photoassimilate production by mature leaves under elevated [CO2] and peak respiratory transcriptional responses. It remains to be determined if biochemical and transcriptional responses to elevated [CO2] in primordial and expanding leaves are essential prerequisites for subsequent alterations of respiratory metabolism in mature leaves.